Apparatus for making stems for electrical devices



Nov. 14, 1950 w. J. KNocHELv ETAL 2,530,168

APPARATUS Foa MAKING sTEMs EoR ELECTRICAL DEVICES anew/w ar 14057' yg 15 T055 Nov. 14, 1950 w. J. KNocHl-:L ET'AL 2,530,168

APPARATUS FOR MAKING s'IRMs RoR ELECTRICAL DEVICES Filed sept. 24, 194e 2 sheets-sheet 2 INVENTORS Awww/L Patented Nov. 14, 1950 APPARATUS FOR MAKING STEMS FOR ELECTRICAL DEVICES William John Knochel, East Orange, and Charles Wiener, Bloomfield, N. J., assignors to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application September 24, 1946, Serial No. 698,914

7 Claims.

This invention relates to stem making and, more particularly, to the prevention of overoxidation of stem leads during manufacture.

The principal object of our invention, generally considered, is to facilitate the manufacture of stems, and particularly those with unbeaded Kcvar leads, as well as avoiding shrinkage due to over-oxidation of such leads.

Another object of our invention is to reduce the time that such Kovar leads are exposed to oxidizing heat during incorporation in a stem, thereby preventing over-oxidation.

A further object of our invention is to avoid over-oxidation of Kovar leads, by speeding up the pressing of stems incorporating the same, and following a first pressing by another a few seconds before the stem-making machine indexes to the next position.

'A still further object of our invention is to improve on the machine formaking stems, and particularly those having unbeaded Kovar leads, by transferring the operating means for the pressing jaws from the Geneva drive shaft cam to a larger cam on the continuous driving Shaft which operates the gear on the Geneva shaft, and adjusting such in position on Asaid drive shaft.

An additional object of our invention is to include a second frog on said driving shaft cam, and provide for varying it in position so as to control the time between pressing operations in the manufacture of stems.

.Other objects and advantages of the invention will become apparent as the description proceeds.

Referring to the scale drawing:

Figure 1 is aplan of a stem-making machine embodying our invention.

Figure 2 is Va fragmentary elevational view of said machine, on a larger scale and with a part in .vertical section.

A Figure 3 is a fragmentary horizontal sectional view on the line III- III of Figure 2, in the direction of the arrows.

Figure 4 is a fragmentary elevational view, corresponding to Figure 2, but showing a subsequent positionjin which the pressing jaws are together in pressing engagement with positioned stem elements.

Figure' is a View, corresponding to Figure 4, but showing a subsequent position in which the jaws have beenwithdrawn from pressing engagement with'a formed stem.

Figure 6 is a diagram illustrating the sequence of events in forming a stem in accordance with our invention. w

Figure '7 is an elevational view of a completed stem.

The present invention is concerned with the prevention of over-oxidation of leads for electrical devices, and particularly of unbeaded Kovar leads during stem making.

In making stems, in accordance with our invention, al1 of the conventional steps are employed except that the pressing time, which occurs after the machine indexes at the nal heating and pressing operation point, is reduced to a degree that over-oxidation of the lead wire cannot take place. In accordance with the normal procedure, a long heat soaking is employed after the pressing jaws operate. We have, therefore, provided for a second pressing operation to occur a few seconds before the machine indexes to the next position.

In accordance with our invention, such a second pressing operation is designated to perform two functions:

1. It makes positive the complete ow of glass around the lead wires. v

2. It shapes the stem and prevents heavy nonuniform sections of glass from forming, which later causes cracked presses.

In order to effect such control, the normal stem machine has been modified.` Previously, the' pressing time was controlled by'a frog on a small cam that was located on the drive shaft for the Geneva and which, therefore, could only operate shaft which causes the Geneva drive shaft tov By proper positioning of a frog on the move. cam, the first pressing operation can be controlled from one second after to one second before the indexing takes place. A second pressing operation is caused to occur by the addition of a port I4. The hub l5 of said conveyor carries,

a Geneva driven member or star wheel I6 and rests on a plate or washer Il, in turn supported on anti-friction means, such as a ball or roller bearing I8.

The conveyor carries a plurality of heads I9 having upwardly opening pockets 2l, each carrying a split generally cylindrical plug 22, in each of which may be held leads 23 and 24, and on each of which may be supported a nare tube 25 and an exhaust tube 26. Although not limited, thereto, we are assuming that the leads 23 and 24 are made of Kovan or similar cxidizable metal, as they are the kind that we are especially concerned with for the prevention of oxidation.

In the present embodiment, the conveyor I2 is operated by power means such as a motor, or other prime mover 21, having a pulley 28 over which a belt 29 passes to a pulley 3l on a shaft 32, carrying a worm 33 meshing with a gear 34 on a continuous drive shaft 35. Said drive shaft f 35 is mounted for rotation in the table or support I4, and a bracket 3S extending from a portion thereof, as shown most clearly in Figure 2. Said shaft 35 carries a gear 31 which is mutilated by having teeth removed therefrom around a large 1;

proportion of its circumference, as illustrated, so that the drive gear 38 with which it engages, and which is mounted on the Geneva drive shaft 39, is stationary for a considerable part of the operating time. The upper portion of the shaft 39 carries a Geneva-star-wheel operating member or driver 4I, a portion 42 of which sequentially engages the slots 43 in the Geneva I6 to effect intermittent rotation of the latter.

FMounted above the iinal heat and pressing station 44 are a pair of pressure jaws 45 and t6, pivoted to an arm 41, projecting from the upper portion ofthe standard or shaft i3 about which the conveyor I2 rotates, as indicated at 43 and 49. These jaws are connected to a bracket 5I, by means of links 52 and 53 pivoted respectively to said bracket 5I and bell-crank arms 54 and 55 projecting from the jaws and 4S, respectively. The bracket 5i is carried by a rod 52, reciprocating in the standard I3, and operated by a lever' 5'1- pivoted to the base I4, as indicated at 58, urged upwardlyby an operati-ng spring 5S, and bifucated laterally and vertically at its end to receive said rod 56 and projections 6I on the lower portion thereof. 'I'he lever 51 carries a roller 62 pivoted as indicated at 63, and urged into engagement witlra cam 54 carried on the lower end of the same shaft 35 that drives lthe conveyor I2. The. cam S4 comprises a plate carrying a pair of frogs, 65 and` SQ, adjustably secured thereto, as by bolts 61 and 68 movable in arcuate slots 69 and -l I., respectiveiy.v

Mountedon. the support I4 are several gas pipes. 'I 2.terminating in burner nozzles adapted to provide fires` 73., '14, 15, and "IB, at preheating stations Il and 78iinal heating and pressing station 44 andannealing and exhaust tube opening station 19. The res at preheating station 'Il are relatively mild, those at station 18 are hotter, while thosev at station 44 are adapted to effect the final heating for softening the glass sufciently forV the pressing operations. The res at station 'i9 are merely sufficient to allow for openin g the exhaust tube and effecting annealing.

,The operation of the machine for the practice of our invention may be as follows: All of the res are lighted and a flare 25, an exhaust tube 26, and a pail` of leads 23 and 24 are placed in thehead at the station preceding preheating statiorr'IT and labeled charging in Figure 1. As

Y 4 the conveyor I2 is turned during operation by the drive motor 2, through the chain of gears previously described, the assembled stern parts successively index at stations 'il and i6, where they are sufficiently preheated, and then at station 44 where they are sufficiently softened by res l5. At the proper time, say about six seconds after indexing, the pressing jaws 45 and 46 move, upon engagement of the frog with the roller 62, causing descent of the rod 56, from the full to the dotted line position illustrated in Figure 2, where they squeeae'the softened flare tube into engagement with the softened exhaust tube about the associated leads.

The pressing sequence is shown in Figure 6, where the complete cycle is indicated as taking seventeen seconds, beginning with the indexing jog 80, and the rst pressing operation occurs, as represented by the jog 8i of the graph. Continued operation of the machine results in release ofthe jaws 4'5 and 4S to the full line position of Figure 2. The next frog 65 then engages the roller 62, again causing the pressing arms 45 and 46 to engage the prepressed stem, as represented by the jog 62 on the graphof Figure 6, and as illustrated in Figure 4, followed by release of the jaws as in Figure 5.

A few seconds after these pressing and release operations, the head carrying the formed stem is moved to the next position, 7S, where the exhaust tube is opened by a Yproperly directed blast ofair from a pipe 83, as shown in Figure l as indicated by the aperture 84 in Figure 7, and the formed stem subjected to the desired anneal ling treatment. This stem is then moved to and indexed at the next station, labeled "discharging, where it may be removed from the machine.

From the foregoing disclosure, it will be seen that we have improved on the manufacture of stems; first, by speeding up the machine from a cycle time of twenty-four seconds to one of seventeen seconds. While previously the pressing jaws acted about thirteen seconds after each head indexed, now the pressing jaws act about six and fourteen seconds, respectively, after such indexing, with the possibility of varying the pressing time to any desired value. The change in cycle time allows for a gain of approximately 25% in production, while the change in pressing results ina shrinkage decrease from between 50% and to between 1/2% and 1%. A metallurgical check has revealed that the quality of stems produced, in accordance with our invention, is very good and that a great deal of latitude now exists in the control of lead wire oxidization.

Although a preferred embodiment of our invention has been disclosed, it will be understood that modifications may be made within the spirit and scope of the appended claims.

The Lernpert et al. Patent No. 2,279,831, dated April- 14', 1942, is referred to for the formula of Kovar.

We claim: l. Apparatus for making stems for electrical devices comprising a conveyor for supporting and moving assembled glass stem parts and leads,`

res for heating said parts', jaws for at one location performing all of the following operations:

75 means, mechanism between said power meansand` conveyor for intermittently driving the latter, and mechanism between said power means and jaws for causing the latter to effect said double pressing operation.

2. Apparatus for making stems for electrical devices comprising means for heating an assembled glass flare, glass exhaust tube, and leads for a relatively short period of time until the glass parts are sufliciently softened for consolidation, and means comprising a power-operated plate carrying a pair of adjustable cam elements for at one location performing all of the following operations: pressing said softened glass parts to consolidate them about said leads, and shortly thereafter repeating the pressing operation.

3. Apparatus for making stems for electrical devices comprising meansl for heating an assembled glass, flare tube, glass exhaust tube, and leads, for about six seconds, in a given position, until they are sufficiently softened for working, and means comprising a power-operated plate carrying a pair of adjustable cam elements for then at one llocation performing all of the following operations: pressing said partsv to consolidate the flare and exhaust tube with respect to said leads, and repeating the pressing operation about eight seconds later, in order to make positive the complete flow of glass around the leads and shape the stem, preventing heavy non-uniform sections of glass from forming.

4. Apparatus for making stems for electrical devices comprising a conveyor, heads thereon for supporting assembled stem parts, means for heating said assembled parts, pressing jaws pivoted adjacent said conveyor to act on said parts after heating, means pivoting conveyor for rotation about a vertical axis, means for intermittently rotating said conveyor about said axis comprising a Geneva star Wheel on said conveyor, a driver therefor, a shaft carrying said driver, a gear on said shaft, a drive shaft for said conveyor, a drive gear mounted on said shaft and mutilated so that it periodically engages and disengages with respect to the gear on said driver-carrying shaft, so that said conveyor is periodically indexed from station to station, a jaw-operating cam device mounted on said drive shaft and provided with adjustable cam elements, an operating arm, means pivoting said arm in cooperative association with said cam device, mechanism for conveying motion from said arm to said jaws, means to normally hold said jaws in open position, and means on said arm engaged by said adjustable cam elements for periodically closing said jaws to rst effect consolidation and then effect shaping of each stem being manufactured.

5. Apparatus for making stems .for electrical devices comprising a conveyor, heads thereon for supporting assembled stem parts, means for heating said parts, pressing jaws pivoted adjacent said conveyor to act on said parts after heating, means pivoting said conveyor for rotation about a vertical axis, means for intermittently rotating said conveyor about said axis comprising a Geneva star wheel on said conveyor, a driver therefor, a shaft carrying said driver, a gear on said shaft, a drive shaft for said conveyor, a drive gear mounted on said shaft and formed so that it periodically engages and disengages with respect to the gear on said driver-carrying shaft, so as to effect desired movement of said conveyor, a jaw-operating cam mounted on said shaft and comprising a plate with a plurality of adjustable frogs secured thereto, an operating arm, means pivoting said arm in cooperative association with said cam, mechanism for conveying motion from said arm to said jaws, resilient means acting on said arm to normally hold said jaws in open position, and a roller pivoted to said arm and periodically engaged by said frogs for first closing and opening and then again closing and opening said jaws withrrespect to each group of assembled stem parts.

6. Apparatus for making stems for electrical devices comprising a conveyor, heads thereon for supporting assembled stem parts, means for heating said assembled parts, pressing jaws pivoted adjacent said conveyor to act on said parts after heating, a standard about which said conveyor rotates, a Geneva star wheel carried by said conveyor, a drive shaft, a drive gear mounted on said shaft and mutilated so that it periodically engages and disengages, a gear engageable by said mutilated gear, a shaft carrying said engageable gear, a driver on said shaft for said Geneva star wheel, a jaw-operating cam mounted on said drive shaft and comprising a plate with a plurality of adjustable elements secured thereto, and mechanism for conveying motion from said adjustable elements to said pressing jaws in order to cause them to close, open, and then again close and open with respect to each set of assembled stem parts while the latter are in softened condition.

7. Apparatus for making stems for electrical devices comprising a conveyor, heads thereon for f supporting assembled stem parts, means for heating said assembled parts, pressing jaws pivoted above said conveyor to act on said parts after heating, a standard about which said conveyor rotates, a Geneva star wheel carried by said con'- veyor, a shaft for turning said conveyor, a Geneva star wheel driver mounted on said shaft, a gear mounted on said driver carrying shaft, a drive shaft, a drive gear mounted on said drive shaft and mutilated so that it periodically engages and disengages with respect to said driver-carrying shaft gear, a jaw-operating cam mounted on said drive shaft and comprising a plate with a plurality of adjustable frogs secured thereto, an operating arm, means pivoting said arm in cooperative association with said jaw-operating cam, mechanism for conveying motion from said arm to said pressing jaws, a spring acting on said arm to normally hold said jaws in open position, and a roller carried by said pivoted arm and periodically engaged by said frogs for closing said jaws against the force of said spring.

- WILLIAM JOHN KNOCI-IEL.

CHARLES WIENER.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 872,530 Meeker Dec. 3, 1907 1,338,500 Eisler Apr. 27, 1920 1,579,765 Higgins Apr. 6, 1926 1,640,442 De Jong Aug. 30, 1927 1,655,140 Fagan Jan. 3, 1928 1,655,141 Fagan et al Jan. 3, 1928 1,741,016 Eisler Dec. 24, 1929 

